CN217956543U

CN217956543U - Cable laying traction device for cable laying

Info

Publication number: CN217956543U
Application number: CN202221929925.0U
Authority: CN
Inventors: 刘洋
Original assignee: Jiangsu Rongshuang Hydropower Construction Engineering Co ltd
Current assignee: Jiangsu Rongshuang Hydropower Construction Engineering Co ltd
Priority date: 2022-07-23
Filing date: 2022-07-23
Publication date: 2022-12-02
Anticipated expiration: 2032-07-23

Abstract

The application relates to the technical field of cable laying, in particular to a cable laying traction device for cable laying. The utility model provides a cable laying draw gear of cable laying usefulness, including two at least traction rods, traction wheel and adjustment mechanism, and two at least traction wheels rotate and set up on the traction rod, adjustment mechanism and traction wheel one-to-one, adjustment mechanism includes the head rod, the parent tube, slide bar and first spring, the one end of head rod articulates on the traction rod, the other end and the traction wheel of head rod rotate to be connected, the parent tube articulates on the traction rod, slide bar slides along the parent tube axis direction and sets up on the inside pipe wall of parent tube, the one end that slide bar stretches out the parent tube rotates with the traction wheel to be connected, first spring sets up between slide bar and parent tube, the hinge point of parent tube on the traction rod and the pin joint of head rod on the traction rod are along the axis direction collineation of traction rod. The method and the device can effectively reduce the abrasion condition in the cable laying process.

Description

Cable laying traction device for cable laying

Technical Field

The application relates to the technical field of cable laying, in particular to a cable laying traction device for cable laying.

Background

The cable means a conductor provided with an insulating layer and a protective sheath, which is composed of a plurality of strands of mutually insulated conductors, and is mounted in the air or underground or underwater for telecommunication or power transmission. The underground cable is laid by embedding a cable pipeline underground usually and then penetrating the cable into the embedded cable pipeline. In the process, the cable needs to be pulled to penetrate through the cable duct, and the cable is directly pulled to easily cause the abrasion of the insulating sheath of the cable, so that the hidden danger of use is easily left.

SUMMERY OF THE UTILITY MODEL

In order to reduce the condition that wearing and tearing appear among the cable laying process, this application provides a cable laying draw gear that cable laying used.

The application provides a pair of cable laying draw gear that cable laying used adopts following technical scheme:

the utility model provides a cable laying draw gear that cable laying used, includes traction lever, traction wheel and adjustment mechanism, the traction wheel is equipped with two at least, and at least two the traction wheel rotates and sets up on the traction lever, adjustment mechanism and traction wheel one-to-one, adjustment mechanism includes head rod, parent tube, slide bar and first spring, the one end of head rod articulates on the traction lever, the other end and the traction wheel of head rod rotate to be connected, the parent tube articulates on the traction lever, the slide bar slides along parent tube axis direction and sets up on the inside pipe wall of parent tube, the one end that the slide bar stretches out the parent tube rotates with the traction wheel to be connected, first spring setting is between slide bar and parent tube, the axis direction collineation of the pin joint of head rod on the traction lever and traction lever on the traction lever.

Through adopting above-mentioned technical scheme, traction wheel and pipeline inner wall sliding contact reduce the produced frictional force of traction in-process at the traction, and traction lever head rod and slide bar regard as the base member of traction wheel jointly, and the head rod articulates on the traction lever, and the slide bar slides and sets up in the base pipe, and the base pipe also articulates on the traction lever, thereby makes the traction wheel can adapt to the cable duct of different pipe diameters size. In the cable duct of different pipe diameters size, the traction wheel butt is on the pipeline inner wall promptly, and this in-process head rod and parent tube take place to rotate to the pole that slides slips is at the interior displacement of parent tube, thereby matches the position change of traction wheel. Meanwhile, in the process of changing the position of the traction wheel, the sliding rod automatically slides in the base tube under the elastic action of the first spring to be matched with the position of the traction wheel, and the operation is convenient. In addition, under adjustment mechanism's effect, the traction wheel can the self-adaptation reducing, receives pressure and takes place when warping promptly at pre-buried cable duct, and the traction wheel can automatic adjustment and the butt all the time slides on pre-buried cable duct's inner wall, can effectively reduce the pipe inner wall extrusion traction wheel and lead to the impaired or the traction wheel of pipeline to rotate the difficult condition.

In a specific implementation scheme, one end of the traction rod is rotatably provided with a rotating block, a traction hole is arranged on the rotating block in a penetrating mode, and one end, far away from the rotating block, of the traction rod is provided with a connecting piece used for connecting the bundled cables.

Through adopting above-mentioned technical scheme, the traction hole is connected as outside traction tool's tie point, convenient and outside traction tool. And the rotating block is rotatably arranged on the traction rod, so that the condition that the traction rod rotates due to the rotation of an external traction tool can be effectively reduced, the position of the traction rod in the embedded cable pipeline is relatively stable, and the traction stability is improved.

In a specific can embodiment, the connecting piece includes connecting block, buckle, locking bolt and mounting, the connecting block rotates the one end that sets up at the traction lever and keep away from rotatory piece, the buckle is equipped with two, two the buckle all includes circular arc section and straightway, just the straightway is all connected to the both sides of circular arc section circumference, two the relative butt of circular arc section of buckle is on the cable periphery wall tied in a bundle, locking bolt threaded connection is between the straightway of two buckles, the mounting is used for connecting buckle and connecting block.

By adopting the technical scheme, the arc sections of the two buckles are oppositely abutted against the two sides of the bunched cable and are further locked by the locking bolt, so that the bunched cable and the traction rod are fixedly connected conveniently. Simultaneously, the connecting block is as buckle and the connection media of drawbar, and the connecting block rotates to be set up on the drawbar, can effectively reduce because of the drawbar takes place to rotate and leads to the pivoted condition of bunched cable, can effectively reduce the condition that bunched cable rotated and lead to the tractive difficulty.

In a specific embodiment, the fixing member includes a fixing plate disposed on the clip and a fixing rod disposed between the connecting block and the fixing plate.

Through adopting above-mentioned technical scheme to fixed plate and dead lever cooperate and realize being connected of buckle and connecting block.

In a specific implementation scheme, the two arc sections of the two buckles are both provided with a fixed plate, the two fixed rods are both provided with a supporting piece, the supporting piece comprises a supporting wheel and a first adjusting piece, the two fixed rods are both rotatably provided with the supporting wheel, and the first adjusting piece is arranged on the fixed rods and used for adjusting the positions of the supporting wheels.

By adopting the technical scheme, the two opposite supporting wheels are used as the supporting base bodies of the fixing rods, and the supporting wheels can slide on the inner wall of the pipeline in the traction process, namely the supporting wheels can play a better supporting effect while not influencing the traction effect, so that the damage condition of the fixing rods due to overlarge bearing pressure caused by sinking of the bunched cables is reduced, the bunched cables are kept in the middle position for traction laying, and the abrasion condition of the bunched cables due to friction with the inner wall of the pipeline in the laying process is reduced; and the two supporting wheels are adapted to pipelines with different pipe diameters under the action of the first adjusting piece.

In a specific can implement embodiment, first regulating part includes that first regulation pole, second are adjusted pole, second spring and sliding block, every all slide along dead lever axis direction on the dead lever and set up two sliding blocks, the second spring housing is established on the dead lever, and is same two sliding blocks on the dead lever deviate from the equal fixed connection second spring in one side each other, first regulation pole and second are adjusted the pole and are articulated respectively on two sliding blocks, first regulation pole and second are adjusted the pole and are kept away from the one end of sliding block and all are rotated with the supporting wheel and be connected.

Through adopting above-mentioned technical scheme, when the equidimension pipeline pipe diameter of supporting wheel adaptation, receive the pressure of pipeline inner wall, the supporting wheel tends dead lever one side and removes, and corresponding rotation takes place for first regulation pole and second regulation pole, and the elasticity that the piece of sliding was overcome the second spring simultaneously is kept away from relatively, accomplishes the adaptation of pipe diameter size. And the elasticity of the second spring enables the supporting wheel to be always abutted against the inner wall of the pipeline, so that a certain supporting effect is achieved, and the supporting wheel has positive significance for reducing friction between the bunched cable and the inner wall of the pipeline.

In a specific possible embodiment, a cleaning plate is arranged on the traction rod and abuts against the inner wall of the pipeline used for being matched with the traction device, the cleaning plate is located on one side, close to the rotating block, of the traction wheel, the traction wheel and the supporting wheel are opposite to the cleaning plate along the axis direction of the traction rod, and a second adjusting piece used for adjusting the position of the cleaning plate is arranged on the traction rod.

Through adopting above-mentioned technical scheme, at the in-process that utilizes draw gear to pull bunched cable, the place ahead that the clearance board is located traction wheel and supporting wheel in the direction of pulling can clear up debris on the pipeline inner wall in advance to help reducing and lead to traction wheel and supporting wheel to slide the obstructed condition because of debris influence, help improving bunched cable's traction stability promptly.

In a specific possible embodiment, the second adjusting member includes a second connecting rod hinged to the traction rod and a torsion spring disposed between the second connecting rod and the traction rod, and the cleaning plate is disposed at an end of the second connecting rod away from the traction rod.

Through adopting above-mentioned technical scheme, under the cooperation of second connecting rod and torsional spring for the clearance board can the not pipeline of different pipe diameters size of adaptation, and make the clearance board butt all the time on pipe inner wall, be convenient for clear up the debris on the pipe inner wall.

In summary, the present application includes at least one of the following beneficial technical effects:

1. according to the method, at least two traction wheels are used as contact media of the traction rods and the inner wall of the pipeline, so that friction between the bunched cable and the inner wall of the pipeline can be effectively reduced, the bunched cable can be laid more conveniently, and the condition that the bunched cable is abraded in the laying process can be effectively reduced; in addition, under adjustment mechanism's effect, can make the traction wheel adapt to the pipeline of different pipe diameters size, the suitability is wider.

2. The connecting mode between the rotating block and the traction rod and between the connecting block and the traction rod is set to be in rotating connection, the condition that the bundled cables rotate in the pipeline due to the influence of an external traction tool can be effectively reduced, and the condition that the bundled cables are difficult to pull and lay due to the rotation of the bundled cables is facilitated to be reduced.

3. This application further forms the support in the upper and lower side of two buckles through two relative supporting wheel butt on the pipeline inner wall to can effectively reduce the condition that leads to the dead lever to damage because of the cable afterbody sinks tied in a bundle, and help making cable tied in a bundle keep central point, reduce the cable tied in a bundle promptly because of with the pipe inner wall between the friction and lead to the condition of wearing and tearing.

Drawings

Fig. 1 is a schematic structural diagram of a cable laying traction apparatus for cable laying according to an embodiment of the present application.

Fig. 2 is a sectional view showing the structure of an adjusting mechanism in an embodiment of the present application.

Fig. 3 is an enlarged view at a in fig. 2.

Fig. 4 is an enlarged view at B in fig. 2.

Description of reference numerals: 1. a draw bar; 2. a traction wheel; 3. an adjustment mechanism; 31. a first connecting rod; 32. a base pipe; 33. a slide bar; 34. a first spring; 4. rotating the block; 41. a drawing hole; 5. a connecting member; 51. connecting blocks; 52. buckling; 521. a circular arc section; 522. a straight line segment; 53. locking the bolt; 54. a fixing member; 541. a fixing plate; 542. a fixing rod; 6. a support member; 61. a support wheel; 62. a first adjustment member; 621. a first adjusting lever; 622. a second adjusting lever; 623. a second spring; 624. a sliding block; 7. cleaning the plate; 8. a second adjusting member; 81. a second connecting rod; 82. a torsion spring; 9. and bundling cables.

Detailed Description

The present application is described in further detail below with reference to figures 1-4.

The embodiment of the application discloses cable laying draw gear that cable laying used.

Referring to fig. 1, 2 and 3, the cable laying traction device for cable laying comprises a traction rod 1, traction wheels 2 and an adjusting mechanism 3, wherein at least two traction wheels 2 are arranged, and three traction wheels 2 are arranged in the embodiment. The adjusting mechanism 3 corresponds to the traction wheel 2 one by one, the adjusting mechanism 3 comprises a first connecting rod 31, a base pipe 32, a sliding rod 33 and a first spring 34, one end of the first connecting rod 31 is hinged on the traction rod 1, and the traction wheel 2 is rotatably arranged at the other end of the first connecting rod 31. The base pipe 32 is hinged on the traction rod 1, and a hinged point of the base pipe 32 on the traction rod 1 is opposite to a hinged point of the first connecting rod 31 on the traction rod 1 along the axial direction of the traction rod 1; the sliding rod 33 is arranged on the inner wall of the base pipe 32 in a sliding way along the axial direction of the base pipe 32, and one end of the sliding rod 33 extending out of the base pipe 32 is connected with the traction wheel 2 in a rotating way. A first spring 34 is fixedly connected between the slide bar 33 and the base pipe 32. Meanwhile, the hinge points of the first connecting rods 31 corresponding to the three traction wheels 2 on the traction rod 1 are circumferentially arranged along the traction rod 1, and the hinge points of the base pipes 32 corresponding to the three traction wheels 2 on the traction rod 1 are circumferentially arranged along the traction rod 1.

When laying bunched cable 9, connect the one end that is close to adjustment mechanism 3 with outside traction tool earlier, under the cooperation of head rod 31, parent tube 32 and slide bar 33, the elasticity of first spring 34 makes traction wheel 2 butt all the time on the pipeline inner wall simultaneously, accomplishes the adaptation of traction wheel 2 and pipeline pipe diameter promptly. The drawbar 1 is then moved towards the interior of the pipe so that the drawbar 1 enters the pipe mostly and projects out of the pipe away from the end of the traction sheave 2. And then fixedly connecting the bunched cable 9 to one end of the traction rod 1 extending out of the pipeline, providing traction force through an external traction tool to lay the bunched cable 9, and taking down the traction device after the traction device is pulled out from the other end of the pipeline to finish the laying of the bunched cable 9.

Referring to fig. 2, it is considered that the external pulling tool is easily connected while reducing the difficulty in pulling and laying due to the rotation of the bundled cable 9 during the pulling process. Furthermore, a rotating block 4 is rotatably arranged on the end wall of the traction rod 1 close to the traction wheel 2, and a traction hole 41 is arranged on the rotating block 4 in a penetrating manner.

Referring to fig. 2 and 4, a connecting piece 5 for connecting a bundled cable 9 is arranged at one end of the traction rod 1 far away from the rotating block 4. The connecting piece 5 comprises a connecting block 51, a buckle 52, a locking bolt 53 and a fixing piece 54, wherein the connecting block 51 is rotatably arranged on the end wall of one side of the traction rod 1 away from the rotating block 4; the buckle 52 is equipped with two, and two buckles 52 all include circle-arc section 521 and straightway 522, and straightway 522 is all connected to the both sides of circle-arc section 521 circumference, and the relative butt of circle-arc section 521 of two buckles 52 is on the cable 9 periphery wall tied in a bundle, and locking bolt 53 threaded connection is between the straightway 522 of two buckles 52.

Referring to fig. 2 and 4, the fixing member 54 is used for connecting the buckle 52 and the connecting block 51, the fixing member 54 includes a fixing plate 541 and a fixing rod 542, the middle part of the circular arc section 521 of the two buckles 52 and the side deviating from the bundled cable 9 are fixedly connected with the fixing plate 541, and the fixing rod 542 is fixedly connected between the connecting block 51 and the fixing plate 541.

When an external traction tool is connected, the traction hole 41 on the rotating block 4 is used as a connection point; after the external traction tool is connected, the adaptive operation between the traction wheel 2 and the pipeline is carried out, then the two buckles 52 are relatively abutted against the outer peripheral wall of the bunched cable 9, the bunched cable 9 is clamped between the circular arc sections 521 of the two buckles 52, and then the locking bolt 53 is in threaded connection between the straight sections 522 of the buckles 52, so that the two buckles 52 are relatively abutted against the bunched cable 9, and the fixed connection between the bunched cable 9 and the traction rod 1 is completed. And then, an external traction tool is used for providing tension for the traction device to lay the bunched cable 9 until the bunched cable 9 extends out of the other end of the pipeline, and the traction device is taken down to finish the laying work of the bunched cable 9.

Referring to fig. 2 and 4, it is considered that damage to the fixing rods 542 due to sinking of the tail portion of the bundled cable 9 is reduced, and meanwhile, the bundled cable 9 is kept to be laid in the center in the pipeline as much as possible, and abrasion of the bundled cable 9 is reduced. Further, support members 6 are arranged on the two fixing rods 542, each support member 6 includes a support wheel 61 and a first adjusting member 62, the two support wheels 61 are respectively located on two sides of the two fixing rods 542, the two fixing rods 542 deviate from each other, the first adjusting member 62 includes a first adjusting rod 621, a second adjusting rod 622, a second spring 623 and a sliding block 624, the sliding block 624 is sleeved on the fixing rods 542, and two sliding blocks 624 are arranged on each fixing rod 542 in a sliding mode along the axial direction of the fixing rod 542. The second spring 623 is sleeved on the fixing rod 542, one sides of the two sliding blocks 624, which are away from each other, on the same fixing rod 542 are fixedly connected with the second spring 623, and one end of the second spring 623, which is away from the sliding block 624, is fixedly connected with the connecting block 51 or the fixing plate 541. The first adjusting lever 621 and the second adjusting lever 622 are respectively hinged to the two sliding blocks 624, and one ends of the first adjusting lever 621 and the second adjusting lever 622 far away from the sliding blocks 624 are rotatably connected to the supporting wheel 61.

When the traction wheel 2 and the inner diameter of the pipe are adapted, the support wheel 61 is also adapted to the inner diameter of the pipe by adjusting the positions of the first adjusting lever 621, the second adjusting lever 622 and the sliding block 624. In the process that the supporting wheel 61 is adapted to the inner diameter of the pipeline, the included angle between the first adjusting lever 621 and the second adjusting lever 622 changes, and the two sliding blocks 624 are relatively far away on the fixing rod 542 against the elastic force of the second spring 623. In the process of laying the bunched cable 9, the two supporting wheels 61 are relatively abutted against the inner wall of the pipeline to slide, and play a certain supporting role in the traction end of the bunched cable 9.

Referring to fig. 1 and 2, it is considered that the supporting rollers 2 and the supporting rollers 61 are affected by the foreign matters on the inner wall of the pipe, thereby preventing the bundled cable 9 from being normally laid. Further, a cleaning plate 7 is fixedly connected to the drawbar 1. The cleaning plate 7 is abutted against the inner wall of the pipeline, the cleaning plate 7 is opposite to the traction wheel 2 or the supporting wheel 61 along the axial direction of the traction rod 1, and meanwhile, the cleaning plate 7 is positioned on one side, close to the rotating block 4, of the traction wheel 2.

Referring to fig. 1 and 2, the drawbar 1 is provided with a second adjustment member 8 for adjusting the position of the cleaning plate 7. The second adjusting part 8 comprises a second connecting rod 81 and a torsion spring 82, the second connecting rod 81 is hinged to the traction rod 1, the torsion spring 82 is fixedly connected between the second connecting rod 81 and the traction rod 1, and the cleaning plate 7 is fixedly connected to one end, far away from the traction rod 1, of the second connecting rod 81.

Before the traction wheel 2 and the supporting wheel 61 are adapted to the inner diameter of the pipeline, the second connecting rod 81 is rotated against the elasticity of the torsion spring 82, and the cleaning plate 7 is abutted on the inner wall of the pipeline. In the laying process of the bunched cable 9, the cleaning plate 7 positioned in front of the traction direction can clean sundries on the inner wall of the pipeline in advance, so that the subsequent traction wheel 2 and the supporting wheel 61 can roll on the inner wall of the pipeline stably, and the stability of the laying process of the bunched cable 9 is improved.

The implementation principle of the cable laying traction device for cable laying in the embodiment of the application is as follows: in the process of laying the bunched cable 9, one end of the traction rod 1 is connected with an external traction tool, then the cleaning plate 7, the traction wheel 2 and the supporting wheel 61 are matched with the inner diameter of the pipeline, and the other end of the traction rod 1 is connected with the bunched cable 9 through the connecting piece 5. Then traction force is provided through an external traction tool, and the bunched cable 9 is pulled under the action of a traction device; meanwhile, in the traction process, the cleaning plate 7 firstly cleans sundries on the inner wall of the pipeline, and meanwhile, the traction wheel 2 and the supporting wheel 61 are always abutted against the inner wall of the pipeline to roll, so that the traction resistance is reduced, the friction between the bunched cable 9 and the inner wall of the pipeline can be effectively reduced, and the condition that the bunched cable 9 is abraded is reduced.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. The utility model provides a cable laying draw gear that cable laying used which characterized in that: including traction lever (1), traction wheel (2) and adjustment mechanism (3), traction wheel (2) are equipped with at least two, and at least two traction wheel (2) rotate and set up on traction lever (1), adjustment mechanism (3) and traction wheel (2) one-to-one, adjustment mechanism (3) include head rod (31), parent tube (32), slide bar (33) and first spring (34), the one end of head rod (31) articulates on traction lever (1), the other end and the traction wheel (2) of head rod (31) rotate and are connected, parent tube (32) articulate on traction lever (1), slide bar (33) slide along head rod (32) axis direction and set up on the inside pipe wall of parent tube (32), the one end that base tube (32) were stretched out to slide bar (33) rotates with traction wheel (2) and is connected, first spring (34) set up between slide bar (33) and parent tube (32), articulated point and the collinear axis of first pivot point (31) on traction lever (1).

2. A cable-laying traction apparatus for cable laying according to claim 1, wherein: one end of the traction rod (1) is rotatably provided with a rotating block (4), a traction hole (41) penetrates through the rotating block (4), and a connecting piece (5) used for connecting a bunched cable (9) is arranged at one end, far away from the rotating block (4), of the traction rod (1).

3. A cable-laying traction apparatus for cable laying according to claim 2, wherein: connecting piece (5) include connecting block (51), buckle (52), locking bolt (53) and mounting (54), connecting block (51) rotate to be set up in traction lever (1) and keep away from the one end of rotatory piece (4), buckle (52) are equipped with two, two buckle (52) all include circular arc section (521) and straightway (522), just straightway (522) are all connected to the both sides of circular arc section (521) circumference, two circular arc section (521) relative butt of buckle (52) is on bunched cable (9) periphery wall, locking bolt (53) threaded connection is between straightway (522) of two buckles (52), mounting (54) are used for connecting buckle (52) and connecting block (51).

4. A cable-laying traction apparatus for cable laying according to claim 3, wherein: the fixing piece (54) comprises a fixing plate (541) and a fixing rod (542), the fixing plate (541) is arranged on the buckle (52), and the fixing rod (542) is arranged between the connecting block (51) and the fixing plate (541).

5. A cable-laying traction apparatus for cable laying according to claim 4, wherein: the fixing plates (541) are arranged on the arc sections (521) of the two buckles (52), the supporting pieces (6) are arranged on the fixing rods (542), each supporting piece (6) comprises a supporting wheel (61) and a first adjusting piece (62), the supporting wheels (61) are arranged on the fixing rods (542) in a rotating mode, and the first adjusting pieces (62) are arranged on the fixing rods (542) and used for adjusting the positions of the supporting wheels (61).

6. A cable-laying traction apparatus for cable laying according to claim 5, wherein: first regulating part (62) are including first regulation pole (621), second regulation pole (622), second spring (623) and sliding block (624), every all slide along dead lever (542) axis direction on dead lever (542) and set up two sliding block (624), second spring (623) cover is established on dead lever (542), and is same two sliding block (624) on dead lever (542) deviate from equal fixed connection second spring (623) in one side each other, first regulation pole (621) and second regulation pole (622) articulate respectively on two sliding block (624), the one end that sliding block (624) were kept away from to first regulation pole (621) and second regulation pole (622) all rotates with supporting wheel (61) and is connected.

7. A cable-laying traction apparatus for cable laying according to claim 4, wherein: be provided with cleaning plate (7) on traction lever (1), cleaning plate (7) butt is being used for the cooperation on the pipeline inner wall that draw gear used, cleaning plate (7) are located one side that traction wheel (2) are close to rotatory piece (4), just traction wheel (2) and supporting wheel (61) all are relative with cleaning plate (7) along the axis direction of traction lever (1), be provided with second regulating part (8) that are used for adjusting cleaning plate (7) position on traction lever (1).

8. A cable-laying traction apparatus for cable laying according to claim 7, wherein: the second adjusting piece (8) comprises a second connecting rod (81) and a torsion spring (82), the second connecting rod (81) is hinged to the traction rod (1), the torsion spring (82) is arranged between the second connecting rod (81) and the traction rod (1), and the cleaning plate (7) is arranged at one end, far away from the traction rod (1), of the second connecting rod (81).